Underwater series-parallel hybrid manipulator with motion redundancy

Abstract

The application discloses an underwater serial-parallel hybrid manipulator with motion redundancy, comprising an end effector, a two-degree-of-freedom 2R serial mechanism, a six-degree-of-freedom 2-RRRPRS-RRRPRRU motion-redundant parallel mechanism and a base mounting rack; the serial-parallel hybrid mechanism improves the motion accuracy, structural stiffness and reliability of the underwater manipulator while ensuring sufficient working space. The motion-redundant design is realized by adopting a planar five-link two-degree-of-freedom mechanism and a swing rod, and the parallel mechanism can avoid singular configurations through coordinated control of multiple driving elements in a branch. The motion-redundant design can avoid singular configurations of the parallel mechanism, expand the working space of the parallel mechanism, improve the motion performance of the underwater manipulator, increase the dexterity of the mechanism and improve the structural stiffness and load-carrying capacity of the mechanism, so that the underwater manipulator can better adapt to the complex and changeable working environment underwater.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of underwater operation robots, and particularly relates to a serial-parallel hybrid underwater manipulator with motion redundancy. BACKGROUND

[0002] As an important tool for underwater robots to develop marine resources and perform underwater operations, the underwater manipulator directly affects the reliability and work efficiency of underwater operations.

[0003] In view of the large accumulated error of joints and poor rigidity of the common serial underwater manipulator in the working process at the present stage, some scholars and enterprises have proposed using a parallel underwater manipulator in recent years to improve the motion accuracy and structural rigidity of the manipulator. However, it is found in actual application that the working space of the parallel manipulator is small, so that the motion range of the moving platform is limited, and only small-amplitude translation and rotation can be achieved. On the other hand, when the parallel mechanism moves to the vicinity of the singular position, the accuracy decreases, the stress condition deteriorates, and even the degrees of freedom of the mechanism change, which leads to a sharp increase in the force or torque required to drive the parallel mechanism, generates a large internal stress in the component, and may cause component damage, mechanism instability, and changes in degrees of freedom, resulting in uncontrollable mechanism, mechanical failure, and safety hazards. The above problems limit the further popularization and use of the parallel manipulator. SUMMARY

[0004] The technical problem to be solved by the application is to provide a serial-parallel hybrid underwater manipulator with motion redundancy to solve the technical problems of small working space and mechanism singularity of the existing robot in view of the deficiencies in the prior art.

[0005] The application adopts the following technical scheme:

[0006] The serial-parallel hybrid underwater manipulator with motion redundancy comprises a six-degree-of-freedom 2-RRRPRS-RRRPRRU motion redundancy parallel mechanism, one end of the six-degree-of-freedom 2-RRRPRS-RRRPRRU motion redundancy parallel mechanism is installed on a base mounting frame 20, and the other end is connected to an end effector through a two-degree-of-freedom 2R serial mechanism.

[0007] The six-degree-of-freedom 2-RRRPRS-RRRPRRU motion redundancy parallel mechanism comprises two RRRPRS motion redundancy branch chains and one RRRPRRU motion redundancy branch chain, the RRRPRS motion redundancy branch chain and the RRRPRRU motion redundancy branch chain are connected in parallel, R is a revolute pair, P is a prismatic pair, S is a spherical pair, and U is a universal joint.

[0008] Specifically, the two-degree-of-freedom 2R series mechanism comprises a forearm link, one end of the forearm link is connected with an end effector, the other end of the forearm link is connected with one end of a large arm link through a first waterproof servo, the other end of the large arm link is connected with a moving platform of a six-degree-of-freedom 2-RRRPRS-RRRPRRU motion-redundant parallel mechanism through a second waterproof servo.

[0009] Further, the moving platform and one end of the large arm link are respectively provided with a servo fixing frame for mounting the first waterproof servo and the second waterproof servo.

[0010] Further, the forearm link and the first waterproof servo, and the large arm link and the second waterproof servo are respectively connected through U-shaped supports.

[0011] Further, the two ends of the forearm link and the large arm link are respectively provided with connecting plates.

[0012] Specifically, one end of two RRRPRS motion-redundant branches and one RRRPRRU motion-redundant branch is connected with the moving platform, the moving platform is connected with the two-degree-of-freedom 2R series mechanism, the RRRPRS motion-redundant branch is connected with the moving platform through a spherical bearing, and the RRRPRRU motion-redundant branch is connected with the moving platform through a universal hinge.

[0013] The other end of the two RRRPRS motion-redundant branches and the one RRRPRRU motion-redundant branch is connected with a base fixed platform, the base fixed platform is fixedly connected with a base mounting frame, and the RRRPRS motion-redundant branch and the RRRPRRU motion-redundant branch are provided with waterproof servos.

[0014] Further, the base fixed platform is in a Y-shaped structure, the RRRPRS motion-redundant branch and the RRRPRRU motion-redundant branch are arranged at intervals of 120°, and the moving platform is in a triangular structure.

[0015] Specifically, the RRRPRS motion-redundant branch comprises a third waterproof servo and a fourth waterproof servo, the third waterproof servo and the fourth waterproof servo are connected with the base fixed platform and serve as rotary pairs for driving the RRRPRS motion-redundant branch.

[0016] The third waterproof servo is connected with one end of a first connecting link through a servo plate, the fourth waterproof servo is connected with one end of a first swing guide rod through a servo plate, the other end of the first swing guide rod is assembled with a first sliding groove link to form a moving pair with a limiting function, the first connecting link and the first sliding groove link are connected through a first link, one end of a first swing link is connected with the first connecting link and the first sliding groove link at a rotary pair to form a compound hinge, and the other end of the first swing link is connected with a spherical bearing.

[0017] Specifically, the RRRPRRU motion redundant branch chain comprises a fifth waterproof steering engine and a sixth waterproof steering engine, the fifth waterproof steering engine and the sixth waterproof steering engine are connected with the base fixed platform and are used as rotating pairs to drive the RRRPRRU motion redundant branch chain.

[0018] The fifth waterproof steering engine is connected with one end of the second connecting link through a steering disc, the sixth waterproof steering engine is connected with one end of the second swing guide rod through a steering disc, the other end of the second swing guide rod is assembled with the second sliding groove connecting rod to form a moving pair with a limiting function, the second connecting link is connected between the second connecting link and the second sliding groove connecting rod, the rotating pair where the second connecting link is connected with the second sliding groove connecting rod is connected with one end of the second swing rod to form a compound hinge, the other end of the second swing rod is connected with one end of the third swing rod to form a rotating pair, and the other end of the third swing rod is connected with the universal hinge.

[0019] Specifically, the end effector comprises a dredging reamer head, and the dredging reamer head is connected with the two-degree-of-freedom 2R series mechanism through a dredging reamer base.

[0020] Compared with the prior art, the present application has at least the following beneficial effects:

[0021] The underwater serial-parallel hybrid manipulator with motion redundancy can ensure sufficient working space while improving the motion accuracy, structural rigidity and reliability of the underwater manipulator. The planar five-link two-degree-of-freedom mechanism cooperates with the swing rod to realize the motion redundancy design, and the singular positions of the parallel mechanism can be avoided through the coordinated control of the multiple driving elements in the branch chain. The motion redundancy design can avoid the singular positions of the parallel mechanism, expand the working space of the parallel mechanism, improve the motion performance of the underwater manipulator, increase the dexterity of the mechanism, and improve the structural rigidity and carrying capacity of the mechanism, so that the underwater manipulator can better adapt to the complex and variable underwater working environment.

[0022] Further, the six-degree-of-freedom 2-RRRPRS-RRRPRRU motion redundant parallel mechanism has six degrees of freedom as a whole, and the moving platform has only two rotational degrees of freedom and one translational degree of freedom, i.e. three relative degrees of freedom (also known as link degrees of freedom) relative to the base moving platform. Since the relative degrees of freedom are less than the overall degrees of freedom of the mechanism, the mechanism is a motion redundant parallel mechanism (also known as a structure redundant parallel mechanism). When the moving platform of the parallel mechanism is parallel to any swing rod in the three branch chains during motion, the parallel mechanism is in a singular position, the instantaneous degrees of freedom of the mechanism change, the stress condition deteriorates, and even the mechanism becomes unstable, which limits the working space of the mechanism, and the motion redundancy mode needs to be used to avoid it. When the parallel mechanism is singular, the two drivers of the planar two-degree-of-freedom five-link mechanism in the branch chain coplanar with the moving platform can be controlled to move coordinately to make the swing rod and the moving platform non-coplanar, so that the structure is away from the singular position, thereby achieving the purpose of avoiding the singular position of the mechanism.

[0023] Further, the base platform is in Y-shaped structure as a whole, and the moving platform is in triangular structure as a whole, so that each branch chain is arranged at intervals of 120° from each other while the volume of the moving platform is minimized, thereby reducing the weight of the mechanical arm and the fluid resistance.

[0024] Further, the singular position of the parallel mechanism is avoided by using the motion redundancy design method, the working space of the moving platform of the parallel mechanism is expanded, and the motion performance of the mechanism is improved. The motion redundancy design method changes the parallel mechanism branch chain originally having only a single driving element into a branch chain having multiple driving elements, thereby improving the degree of freedom of the branch chain and the whole mechanism. Through the cooperative motion of multiple drivers, the parallel mechanism can be away from the partial singular position, that is, the singular position is avoided by the motion redundancy. The motion redundancy can expand the motion range of the moving platform of the mechanism, improve the dexterity, avoid the singular position, avoid the stress deterioration or instability of the mechanism, and improve the reliability of the underwater mechanical arm system, so that the underwater mechanical arm system can better adapt to the harsh underwater working environment.

[0025] Further, the motion redundancy parallel mechanism improves the motion performance of the parallel mechanism. In addition to the function of avoiding the singular position, compared with the non-redundant parallel mechanism, the motion redundancy mechanism improves the dexterity of the mechanism, and improves the structural stiffness and carrying capacity of the mechanism; compared with the driving redundancy design of directly adding a driver to the passive joint, the motion redundancy design does not cause large internal stress in the mechanism due to uncoordinated driving control allocation, has lower requirements for the synchronism and coordination of the control system, reduces the motion control difficulty, and has wide development and application prospect.

[0026] Further, the mechanical arm with the series-parallel hybrid mechanism as the main configuration is applied to underwater operation. The underwater series-parallel hybrid mechanical arm combines the characteristics of the series mechanism and the parallel mechanism. The parallel platform base improves the stiffness and reliability of the mechanical arm system, and the series joint expands the working space of the parallel mechanism, solves the problems of large cumulative error and low stiffness of the series mechanical arm joint and the problem of small working space of the parallel mechanism, and comprehensively balances the performance parameter indexes such as the motion accuracy, structural stiffness, working space and reliability of the underwater mechanical arm, so that the underwater mechanical arm can better adapt to the complex and changeable underwater working environment.

[0027] In summary, the present application has the characteristics of high flexibility, large stiffness, large working space, motion redundancy and high reliability, and provides a new solution for the underwater mechanical arm operation system, and improves the motion performance and working efficiency of the underwater mechanical arm.

[0028] The technical solutions of the present application are described in further detail below by means of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The exploded view of the motion-redundant underwater series-parallel hybrid manipulator of the application;

[0030] Figure 2 The overall structure schematic diagram of the motion-redundant underwater series-parallel hybrid manipulator of the application;

[0031] Figure 3 The mechanism schematic diagram of the motion-redundant underwater series-parallel hybrid manipulator of the application;

[0032] Figure 4 The overall structure schematic diagram of the motion-redundant 2-RRRPRS-RRRPRRU parallel mechanism of the application;

[0033] Figure 5 The RRRPRS motion-redundant branch chain structure schematic diagram of the application;

[0034] Figure 6 The RRRPRRU motion-redundant branch chain structure schematic diagram of the application.

[0035] Wherein: 1. Connecting disc; 2. Dredging reamer head; 3. Dredging reamer base; 4. Forearm connecting rod; 5. U-shaped support; 6. First waterproof steering engine; 7. Steering engine fixing frame; 8. Large arm connecting rod; 9. Second waterproof steering engine; 10. Moving platform; 11. Spherical bearing; 12. First swing rod; 13. First connecting rod; 14. First sliding groove connecting rod; 15. First swing guide rod; 16. First connecting frame rod; 17. Third waterproof steering engine; 18. Fourth waterproof steering engine; 19. Base fixed platform; 20. Base mounting frame; 21. Fifth waterproof steering engine; 22. Sixth waterproof steering engine; 23. Second connecting frame rod; 24. Second swing guide rod; 25. Second sliding groove connecting rod; 26. Second connecting rod; 27. Second swing rod; 28. Third swing rod; 29. Universal hinge. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some but not all of the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the application.

[0037] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "one side", "one end", "one edge" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more. In the description of the application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0038] In the description of the application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0039] It should be understood that when used in the specification and the appended claims, the terms "comprise" and "include" indicate the presence of the described features, whole, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, whole, steps, operations, elements, components and / or sets thereof.

[0040] It should also be understood that the terms used in the specification of the application are only for the purpose of describing specific embodiments and do not intend to limit the application. As used in the specification and the appended claims of the application, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0041] It should be further understood that the term "and / or" used in the specification and the appended claims of the application means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0042] Various structural schematic diagrams according to the disclosed embodiments of the present application are shown in the drawings. These diagrams are not drawn to scale, in which certain details are exaggerated for clarity of presentation and may be omitted. The shapes of various regions, layers shown in the drawings and their relative sizes and positional relationships may deviate in actuality due to manufacturing tolerances or technical limitations, and regions / layers with different shapes, sizes, relative positions may be additionally designed by those skilled in the art according to actual needs.

[0043] The present application provides a kind of underwater series parallel hybrid mechanical arm with motion redundancy, while combining the configuration characteristics of series and parallel two kinds of mechanical arms, take long make up for the short, comprehensive trade-off multiple technical indicators and performance requirements.Simultaneously, for the singular problem of mechanism of the hybrid mechanical arm, singular configuration of parallel mechanism of mechanical arm is avoided using motion redundancy method;So-called redundancy method refers to when the overall degree of freedom of mechanism and the number of driving elements are same and greater than the degree of freedom of end effector, by changing the configuration of each kinematic branch of parallel mechanism, it has redundant degree of freedom, thereby increasing the overall degree of freedom of mechanism.

[0044] The present application designs parallel mechanism with motion redundancy and gets hybrid mechanical arm mechanism configuration combined with series mechanism, improves the overall degree of freedom of hybrid mechanism, so that the mechanism can be realized singular avoidance by motion control, simultaneously improves the carrying capacity and dexterity of mechanism, the overall motion performance of underwater mechanical arm is promoted, can better adapt to a variety of different underwater working environment, meet different underwater operation needs.

[0045] Please refer to Figure 1 The present application provides a kind of underwater series parallel hybrid mechanical arm with motion redundancy, including end effector, two degrees of freedom 2R series mechanism (R represents rotary pair), six degrees of freedom 2-RRRPRS-RRRPRRU (R represents rotary pair, P represents mobile pair, S represents spherical pair, U represents universal joint) motion redundancy parallel mechanism and base mounting frame 20.

[0046] The six-degree-of-freedom 2-RRRPRS-RRRPRRU motion-redundant parallel mechanism is installed on the base mounting frame 20, and one end of the six-degree-of-freedom 2-RRRPRS-RRRPRRU motion-redundant parallel mechanism is connected to the end effector through the two-degree-of-freedom 2R series mechanism; the six-degree-of-freedom 2-RRRPRS-RRRPRRU motion-redundant parallel mechanism and the two-degree-of-freedom 2R series mechanism improve the motion accuracy, structural stiffness and reliability of the underwater manipulator while ensuring sufficient working space; the two-degree-of-freedom 2R series mechanism cooperates with the swing rod to realize the motion-redundant design, and the six-degree-of-freedom 2-RRRPRS-RRRPRRU motion-redundant parallel mechanism can avoid singular configurations through coordinated control of multiple driving elements in the branch chain; the singular configurations of the six-degree-of-freedom 2-RRRPRS-RRRPRRU motion-redundant parallel mechanism are avoided by using the motion-redundant design, the working space of the six-degree-of-freedom 2-RRRPRS-RRRPRRU motion-redundant parallel mechanism is expanded, the motion performance of the underwater manipulator is improved, the dexterity of the mechanism is increased, the structural stiffness and carrying capacity of the mechanism are improved, and the underwater manipulator can better adapt to the complex and variable working environment underwater.

[0047] Please refer to Figure 3 , the overall configuration of the underwater manipulator is a six-degree-of-freedom 2-RRRPRS-RRRPRRU+two-degree-of-freedom 2R hybrid mechanism.

[0048] The end effector comprises a dredging reamer head 2 and a dredging reamer base 3, and the dredging reamer head 2 and the dredging reamer base 3 are connected by screws. The rear end of the dredging reamer base 3 is installed on the forearm flange plate by screws.

[0049] The two-degree-of-freedom 2R series mechanism comprises four connecting plates 1, a forearm link 4, a U-shaped support 5, a first waterproof steering engine 6, an engine fixing frame 7, an upper arm link 8 and a second waterproof steering engine 9.

[0050] The two ends of the forearm link 4 are respectively connected and fixed to the corresponding two connecting plates 1 through flange structures, and the two ends of the upper arm link 8 are respectively connected and fixed to the corresponding two connecting plates 1 through flange structures,

[0051] The long side of the U-shaped support 5 is connected and fixed to the connecting plate 1 corresponding to the rear end of the forearm link 4 by screws, and the short side of the U-shaped support 5 is connected to the first waterproof steering engine 6 through a steering disc to form a forearm motion joint;

[0052] The first waterproof steering engine 6 is installed on the steering engine fixing frame 7 by screws, the steering engine fixing frame 7 is connected and fixed with the connecting disc 1 at the front end of the large arm connecting rod 8 by screws, the long side of the other U-shaped support 5 is connected and fixed with the connecting disc 1 at the rear end of the large arm connecting rod 8 by screws, the short side is connected with the second waterproof steering engine 9 through the steering disc, and the large arm movement joint is formed; the second waterproof steering engine 9 is installed on the other steering engine fixing frame 7 by screws, the other steering engine fixing frame 7 is connected and fixed with the moving platform 10 by screws, so that the two-degree-of-freedom series joint is obtained.

[0053] Please refer to Figure 4 , the six-degree-of-freedom 2-RRRPRS-RRRPRRU motion redundant parallel mechanism includes two RRRPRS motion redundant branch chains and one RRRPRRU motion redundant branch chain, one end of the two RRRPRS motion redundant branch chains and one end of the RRRPRRU motion redundant branch chain are connected with the two-degree-of-freedom 2R series mechanism through the moving platform 10, and the other end of the two RRRPRS motion redundant branch chains and the other end of the RRRPRRU motion redundant branch chain are connected with the base mounting frame 20 through the base fixed platform 19.

[0054] The six-degree-of-freedom 2-RRRPRS-RRRPRRU motion redundant parallel mechanism includes a moving platform 10, a spherical bearing 11, a first swing rod 12, a first connecting rod 13, a first sliding groove connecting rod 14, a first swing guide rod 15, a first connecting frame rod 16, a third waterproof steering engine 17, a fourth waterproof steering engine 18, a base fixed platform 19, a base mounting frame 20, a fifth waterproof steering engine 21, a sixth waterproof steering engine 22, a second connecting frame rod 23, a second swing guide rod 24, a second sliding groove connecting rod 25, a second connecting rod 26, a second swing rod 27, a third swing rod 28 and a universal hinge 29.

[0055] The middle part of the moving platform 10 is connected and fixed with the steering engine fixing frame 7 through threads, as the base of the series mechanism, the periphery of the moving platform is connected and fixed with two spherical bearings 11 and one universal hinge 29 through screws, six waterproof steering engines are connected and fixed on the base fixed platform 19 through screws, two steering engines form a group, and each group is arranged at an interval of 120°, the installation directions of the two steering engines in the same group are parallel and there is a certain interval to prevent structural interference, the base fixed platform 19 is connected and fixed with the base mounting frame 20 through the through hole in the middle part, and the mechanical arm is connected with the underwater robot body through the base mounting frame 20.

[0056] Please refer to Figure 5 , the RRRPRS motion redundant branch chain includes a spherical bearing 11, a first swing rod 12, a first connecting rod 13, a first sliding groove connecting rod 14, a first swing guide rod 15, a first connecting frame rod 16, a third waterproof steering engine 17 and a fourth waterproof steering engine 18.

[0057] The third waterproof steering engine 17 and the fourth waterproof steering engine 18 are connected with the base fixed platform 19 through screws, and are used as rotating pairs to drive the branch chain, the third waterproof steering engine 17 is connected with the first connecting rod 16 through a steering disc, the fourth waterproof steering engine 18 is connected with the first swing guide rod 15 through a steering disc, the first swing guide rod 15 is assembled with the first sliding groove connecting rod 14 to form a moving pair, a limiting screw is installed to limit the moving stroke, so that the moving pair relationship is not damaged, the first connecting rod 13 is connected with the first connecting rod 16 and the first sliding groove connecting rod 14 through two rotating pair joints, and is connected with one end of the first swing rod 12 at the rotating pair joint connected with the first sliding groove connecting rod 14 to form a compound hinge, the other end of the first swing rod 12 is connected with the spherical bearing 11, the base of the spherical bearing 11 is connected with the moving platform 10 and is fixed, so that the RRRPRS motion redundant branch chain is obtained.

[0058] When the first swing rod 12 is coplanar with the moving platform 10, the mechanism is in a singular position, the third waterproof steering engine 17 and the fourth waterproof steering engine 18 are controlled to rotate, so that the mechanism is out of the singular position, the fourth waterproof steering engine 18 is fixed in a general case, and only moves when the mechanism needs to get out of the singular position, which embodies the idea of redundant design.

[0059] Please refer to Figure 6 , the RRRPRRU motion redundant branch chain includes a fifth waterproof steering engine 21, a sixth waterproof steering engine 22, a second connecting rod 23, a second swing guide rod 24, a second sliding groove connecting rod 25, a second connecting rod 26, a second swing rod 27, a third swing rod 28 and a universal hinge 29.

[0060] The connecting and assembling mode of the planar RRRPR mechanism is the same as described above, and will not be repeated here, and the difference is that the second swing rod 27 is connected at the compound hinge of the second planar RRRPR mechanism, the second swing rod 27 is connected with the third swing rod 28 to form a rotating pair, the other end of the third swing rod 28 is connected with the universal hinge 29, and the universal hinge 29 is connected with the moving platform 10 and is fixed, so that the RRRPRRU motion redundant branch chain is obtained. The method for getting out of the singular position through the motion redundancy design of the branch chain is the same as described above, and will not be repeated here.

[0061] The working principle of the underwater serial-parallel hybrid mechanical arm with motion redundancy is as follows:

[0062] The angles of the six rotating pairs R connected with the base fixed platform are controlled to make the planar mechanism in the redundant branch chain move, so as to drive the universal pair U or the spherical pair S connected with the moving platform to produce corresponding trajectory motion, and further make the parallel mechanism moving platform connected therewith realize the specified trajectory motion, on the basis of which, the space motion of the end dredging reamer is realized by controlling the angles of the two rotating joints of the two-degree-of-freedom serial mechanism installed on the parallel mechanism moving platform.

[0063] In summary, the underwater serial-parallel hybrid manipulator with motion redundancy combines the characteristics of serial mechanism and parallel mechanism, takes the advantages and makes up the disadvantages, and comprehensively balances the performance indexes such as motion accuracy, structural rigidity, working space and the like, so as to better adapt to the underwater complex operation environment. On the other hand, the motion redundancy mechanism can increase the carrying capacity and working space of the underwater manipulator while realizing singularity avoidance, so as to avoid the component damage or mechanism out of control caused by the mechanism singularity of the manipulator. The end of the manipulator is coordinated to control the steering gear, so that the dredging reamer can realize the trajectory motion in a large range, and the working efficiency of the underwater dredging operation is improved.

[0064] The above is only used for describing the technical idea of the present application, and cannot be used to limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical scheme falls within the protection scope of the present application.

Claims

1. An underwater series-parallel hybrid manipulator with kinematic redundancy, characterized in that, The six-degree-of-freedom 2-RRRPRS-RRRPRRU motion redundant parallel mechanism is mounted on the base mounting frame 20 at one end and connected to the end effector through the two-degree-of-freedom 2R series mechanism at the other end; The six-degree-of-freedom 2-RRRPRS-RRRPRRU motion redundant parallel mechanism comprises two RRRPRS motion redundant branch chains and one RRRPRRU motion redundant branch chain, the RRRPRS motion redundant branch chain and the RRRPRRU motion redundant branch chain are connected in parallel, R is a rotary pair, P is a moving pair, S is a spherical pair, and U is a universal joint; One end of the two RRRPRS motion redundant branch chains and the one RRRPRRU motion redundant branch chain is connected to the moving platform (10) respectively, the two-degree-of-freedom 2R series mechanism is connected through the moving platform (10), the RRRPRS motion redundant branch chain is connected to the moving platform (10) through the spherical bearing (11), and the RRRPRRU motion redundant branch chain is connected to the moving platform (10) through the universal hinge (29); The other end of the two RRRPRS motion redundant branch chains and the one RRRPRRU motion redundant branch chain is connected to the base fixed platform (19) respectively, and the base fixed platform (19) is fixedly connected with the base mounting frame (20), and the RRRPRS motion redundant branch chain and the RRRPRRU motion redundant branch chain are provided with waterproof steering engines between the base fixed platform (19); The RRRPRS motion redundant branch chain comprises a third waterproof steering engine (17) and a fourth waterproof steering engine (18), the third waterproof steering engine (17) and the fourth waterproof steering engine (18) are connected with the base fixed platform (19) and used as rotary pairs to drive the RRRPRS motion redundant branch chain; The third waterproof steering engine (17) is connected with one end of the first connecting frame rod (16) through a steering disc, the fourth waterproof steering engine (18) is connected with one end of the first swing guide rod (15) through a steering disc, the other end of the first swing guide rod (15) is assembled with the first sliding groove connecting rod (14) to form a moving pair with a limiting function, the first connecting frame rod (16) and the first sliding groove connecting rod (14) are connected through the first connecting rod (13), one end of the first swing rod (12) is connected with a rotary pair between the first connecting rod (13) and the first sliding groove connecting rod (14) to form a composite hinge, and the other end of the first swing rod (12) is connected with the spherical bearing (11); The RRRPRRU motion redundant branch chain comprises a fifth waterproof steering engine (21) and a sixth waterproof steering engine (22), the fifth waterproof steering engine (21) and the sixth waterproof steering engine (22) are connected with the base fixed platform (19) and used as rotary pairs to drive the RRRPRRU motion redundant branch chain; The fifth waterproof steering engine (21) is connected with one end of the second connecting link (23) through a steering disc, and the sixth waterproof steering engine (22) is connected with one end of the second swing guide rod (24) through a steering disc, and the other end of the second swing guide rod (24) is assembled with the second sliding groove connecting rod (25) to form a moving pair with a limiting function, the second connecting link (23) and the second sliding groove connecting rod (25) are connected through the second connecting rod (26), and the second connecting rod (26) is connected with the second sliding groove connecting rod (25) at the rotating pair to form a composite hinge with one end of the second swing rod (27), and the other end of the second swing rod (27) is connected with one end of the third swing rod (28) to form a rotating pair, and the other end of the third swing rod (28) is connected with the universal hinge (29).

2. The underwater series-parallel hybrid manipulator with kinematic redundancy according to claim 1, characterized in that, The two-degree-of-freedom 2R series mechanism comprises a forearm connecting rod (4), one end of the forearm connecting rod (4) is connected with an end effector, the other end is connected with one end of a large arm connecting rod (8) through a first waterproof steering engine (6), the other end of the large arm connecting rod (8) is connected with a moving platform (10) of a six-degree-of-freedom 2-RRRPRS-RRRPRRU motion redundant parallel mechanism through a second waterproof steering engine (9).

3. The underwater series-parallel hybrid manipulator with kinematic redundancy according to claim 2, characterized in that, The moving platform (10) and one end of the large arm connecting rod (8) are respectively provided with a steering engine fixing frame (7) for installing the first waterproof steering engine (6) and the second waterproof steering engine (9).

4. The underwater series-parallel hybrid manipulator with kinematic redundancy according to claim 2, characterized in that, The forearm connecting rod (4) and the first waterproof steering engine (6), and the large arm connecting rod (8) and the second waterproof steering engine (9) are respectively connected through a U-shaped support (5).

5. The underwater series-parallel hybrid manipulator with kinematic redundancy according to claim 2, characterized in that, Both ends of the forearm connecting rod (4) and the large arm connecting rod (8) are respectively provided with a connecting disc (1).

6. The underwater series-parallel hybrid manipulator with motion redundancy according to claim 1, characterized in that, The base fixed platform (19) is a Y-shaped structure, the RRRPRS motion redundant branch and the RRRPRRU motion redundant branch are arranged at an interval of 120°, and the moving platform (10) is a triangular structure.

7. The underwater series-parallel hybrid manipulator with motion redundancy according to claim 1, characterized in that, The end effector comprises a dredging reamer head (2), and the dredging reamer head (2) is connected with the two-degree-of-freedom 2R series mechanism through a dredging reamer base (3).

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